About the On-Base Percentage Calculator
On-base percentage (OBP): how often a batter reaches base via hits, walks or hit-by-pitch.
Also known as: obp calculator, on base pct, reaching base rate.
How to use this calculator
- Enter hits, walks, hit by pitch, at-bats and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)
Worked example
Using the values pre-filled in the calculator above:
- Hits = 152
- Walks = 58
- Hit by pitch = 6
- At-bats = 520
- Sacrifice flies = 5
the calculator returns:
- OBP: 0.367
- Plate appearances: 589
- Times on base: 216